1. Field of the Invention
The present invention relates to a window molding member, for instance for automobiles, as well as a method of manufacturing such molding members.
2. Description of the Related Art
An automobile employs various kinds of molding members, and a typical example thereof is a window molding member adapted to extend along the periphery of front or rear window plate, i.e. along a pair of front or rear pillars and the front or rear edge of the roof panel of the automobile body. A variety of requirements are imposed on molding members mainly from design, cost and/or functional viewpoint, and resulted in an increased demand in the automobile industry for the molding members whose cross-sectional shape varies in the longitudinal direction.
Specifically, one proposal is disclosed for example in Japanese Utility Model Application Publication No. 57-54,416, which is directed to a window molding member having an upper portion with a first predetermined cross-section, and a side portion with a second predetermined cross-section which is different from the first cross-section. When the molding member is arranged along the periphery of a front window plate, the first cross-section of the upper portion contributes to realize a smooth, so-called flush outer surface of the automobile body, while the second cross-section of the side portions serves to define a weir along the side edge of the window plate.
Such an arrangement of the molding member ensures that, during driving in rainy conditions, the weir prevents the rain water from flowing across the side portion toward the side window, effectively preserving the driver's and/or passenger's sight through the side windows.
To produce a window molding member with a cross-section which varies in the longitudinal direction, it has been a conventional practice to make use of a process including preparation of at least two core elements by shaping the raw metal strip into the respectively desired cross-sectional shapes with a roll forming device, etc., placing each core element in the mold of an injection molding machine, and subsequently molding the synthetic resin material into the desired configuration. With such a process, however, since the entire core element of the elongate molding member has to be completely accommodated in the mold, the molding machine as a whole becomes very bulky and requires a substantial space in the factory. Moreover, the process involves relatively complex steps with which the molding members can be produced only one by one, and it is thus difficult to improve the productivity.
Another possibility for producing such molding members is to physically divide each molding member into first and second extruded portions with the respectively predetermined cross-sectional shapes, which are connected with each other either by an injection molding process or by using a separate corner connection piece. However, connection of these portions by means of the injection molding accompanies formation of undesirable burrs along the junctions and resultant deterioration in the appearance, while use of the corner connection piece results in the increased number of the required components and assembly steps.